Metalworking apparatus



Oct. 19, 1943. R. w. ANDREWS, JR., ET A1.

METAL WORKING APPARATUS Filed Aug. 3, 1939 Q 11 RAYNAL W.

4 Sheets-Sheet l 1N VENT ORJ A Na Arr/fuk T. DLF/LY.

A ORNEY.

ANaRzws, JR.

METAL WORKING APPARATUS ATTORNY.'

R. W. ANDREWS, JR., ET AL oct. 19, 1943.,

METAL WORKING APPARATUS 4 sheets-sheet 3 Filed Aug. 3. 1939 INV ENTOR` WAnon-w, JR. AND ARTHUR TD5/Lx ATTORNE'Y.

Oct. 19, 1943. R. w. AND'R|-:ws, JR., ETAL METAL WORKING' APPARATUSFiled Aug. 5, 1939 4 Sheets-Sheet 4 .L L J l I 1 1- L INVENTOR. RAYNAL wANnREwJ, JR. BY ARTHUR T. DEILY.

ATTORNEYy Patented Oct. 19, 1943 UNITED STATES PATENT OFFICEMETALWORKING APPARATUS Raynal 'W. Andrews, Jr., New Kensington, and

Arthur T. Delly, Pittsburgh, Pa., assi gnors to Aluminum Company ofAmerica, Pittsburgh. Pa., a corporation of Pennsylvania ApplicationAugust 3, 1939, Serial No. 288,16; 2 0 Claims. (Cl. 205-7) benches fordrawing tubular shapes, rods and the like through a die. In one specificform the invention relates to a draw bench for drawing tubular shapeswhich employs a die and more than one mandrel rod and bulb.

The usual draw bench for tube drawing comprises a supporting frame orframes upon which are mounted a die, a mandrel and bulb, a draw chain orthe like, and a carriage having jaws for gripping the work after it hasbeen passed over the mandrel and bulb and insertedthrough the die. Thecarriage must be moved to draw the work through the die, and for thismotion 'generally engages with,' and receives its drawing force from, adraw chain or similar device.

When tubular or hollow-shaped material is drawn, a mandrel or bulbdesigned to form the desired inner contour of the work isl usuallyattached to a mandrel rod which may 'be slidably mounted at the rear ofthe mandrel end of the draw bench. The mandrel is customarily supportedmanually while the work is threaded thereover. Ropes and cables havebeen used to force the mandrel rod, bulb, and work into registry withthe die. These operations and such nonpositive methods of registeringbulb and die have resulted in loss of useful production time and wasteof material.

Also in former practices, production has been limited by the timerequired for the return of the drawing carriage to the die head and bythe time required for passing new work over a mandrel rod and bulb.

The generan object of this invention is to im-y objects: The provisionof a plurality of mandrelA Yunits, each `one of which may be employed-inregistry with a die for forming a work-piece during a drawing cycle. Theprovision of such a plurality of mandrel unitsunder such conditions thata new work-piece may be passed over one mandrel unit while a precedingwork-piece is being worked over another mandrel unit in a drawing"cycle.v The provision of positive automatic means for aligning a mandrelunit with a die. 'I'he provision of positive automatic means for forcinga mandrel rod and associatedbulb into registry with a die.

These and further objects and advantages of I.

this invention, either singly or in combination, are for purposes ofconvenience illustrated with respect to a specific mechanism whichembodies all of the specic features of the invention. It

will be understood, however, that these features maybe available forsingle use, or in anysuitable combination, to improve the operation ofdraw benches or similar apparatus", which do not include all of saidfeatures.

In the drawings Fis. 1 isla partial plan view of the preferred form of amechanism embodying the features of the invention, and showing twomandrel rods,

the die head, the drawing carriage, the draw.

same scale as Fig. 2, of the mandrel manipulat Fig. 4 is a section takenon the line IV-IV of I Fig. 3 showing the end mandrel supporting member,the tubular work and mandrel supporting structure, and the piping forthe mandrel manipulating and rotating mechanisms;

Fig. 5 is a section taken on the line V-V of Fig. 3 showing the mandrelrotating mechanism and piping therefor; 4

Fig. 6 is a schematic diagram illustrative of the electric and pneumaticcontrol system for the mandrel rotating and manipulating mechanisms;

Fig. 'I is a side elevation, to an enlarged scale, of the drawingcarriage shown in Fig. 2, in which the work engaging jaws of the drawingcarriage are in a closed position and the draw chain en-` -piece throughthe die.

gagingliook-is ina lowered position, in its first engagement withL thedraw chain:

Fig. 8 is a fragmentary view; partly'in section,

. piece.

shown in Fig. '7, and to the same enlarged scale,

in which one-half is a section taken as indicated by the reference' lineIXe-1X of Fiif. 8.

Briefly, the apparatus as shown comprises a draw bench frame, a drawinghead or carriage,

a drawing die, and two work supporting mandrels. A hollow shape maybepassed over one mandrel within a protecting shell or other guidingsupport by hand or by suitable mechanical loading mechanism (not shown);the mandrels may be rotated to align one work-piece and mandrel with thedie; the point of the work-piece may be inserted through the die; andthe mandrel and work-piece may be forced into registry with the dieconjunctve with the beginning of the drawing action. The drawingcarriage and its work gripping jaws may be actuated to clamp the pointof the hollow shaped work-piece, and may be /moved along the draw benchby suitable engagement with a draw chain to draw the work-A Uponcompletion of a draw, the work-piece may be released to a covenient rackor removal apparatus (not shown).

Endless return means are provided for vauto- Amatically traversing thedrawing carriage back `to the die head after completion of a drawingoperation. Such endless return means are preferably operableindependently of the drawing chain and preferably lare adapted tocontrol the position and rate of speed of the drawing carriage duringits return movement.

It should be noted that the invention provides,

interV alia, for utilizing a plurality of mandrel rods rotatable tobring each, -in its turn, into position for drawing a Work-piece. Aswill appear more fully in the detailed description of the apparatus asshown, means have been provided throughout for automatic operation ofthe draw bench during at least one complete drawing cycle.

` Die section The die section of the draw bench will now be described`with special reference to Figs. 1 and 2 of the drawings. By the diesection is meant that portion of the apparatus immediately head 3 may beremoved from the frame by engagement of a crane hook with an eye-bolt 1.The die head may be suitably shimmed for alignment about the axis ofdraw in one or more planes, or a tilting die head, adjustable abouteither vertical or horizontal axes, can be employed if desired. 'Ihework-piece, here a 'tube 8, is shown with its pointed end 9 insertedthrough die 4. As shown in the sectioned portion of Fig. 2, the

drawing operation has not started, and, there-v fore, mandrel rod I0 andbulb II are not shown lthe protective and supporting shell,

in full registry with die l. Asecond mandrel rod I2 and bulb I3 arelocated above and behind mandrel rod I0 and bulb I I. Said second manedrel rod and bulb are shown-ina fully vretracted position, adapted toreceive an undrawn work- Bulbs II and VI3 are secured to mandrel rods I0and I2,.rcspectively, by suitable threaded nuts I4, preferably taperedoutwardly to facilitate passing of tubular 'and hollow-shaped stockthereover.

Means not necessarily forming part of this invention may be provided forplacing a workpiece on the mandrel when it is in the position of mandrelI2. Means are shown, however, for rotating the mandrel rods to bring themandrel lrod and work-piece from the position of mandrel rod I2 to thelateral position of mandrel rod IIJ; and means arev provided foradvancing a mandrel rod and its work-piece to the die to occupy theposition of mandrel rod III, bulb II, and tubular work-piece 8, asshown.

Means are provided for protecting and supporting a work-piece passedover a mandrel rod and bulb. 'I'hese means preferably take the form oftubular shells I6 supported at convenient intervals along their lengthby mandrel supports 24` intervals within the shells I 6 and providefur-- ther points of support forthe work-piece. Tubular shells I6 aredesigned to protect the work against scratching and dirt and, withbushings I 8 and .22, to support work of considerable length. Whereprotection of the work from dirt is not a primary problem, the shells I6 may take the form of spaced sections or rings rather than continuouslengths of tubing as shown.

Drawing section Referring to Figs. /1, 2, 7, 8 and 9, the drawingsection of the draw bench is now described. This section of the bench isdefined as that portion of thev bench, including the associated appa'-ratus, over which the stock is pulled or drawn fromv the die 4. Thedrawing section comprises generally frame I, draw head 30, and ytracks,or rails 3| along whichthe carriage may move on carriage wheels 32.Gripping jawsI i "fand 34 are located in "draw head 30 and are adaptedto engage the pointed end 9 of the tubular fworkpiece 8. Carriage hook35 is adapted to engage endless draw chain 36. A pair of suitable returnchains or other endlessdriving means 31 and 38 are connected to carriage30 on either side l thereof and adapted to return the carriage toLocking are located along the main frame I, as shown.

These limit switches are arranged to control acceleration anddeceleration'of drawing carriage 30 during its forward drawing andreturn move'- ments, and further to control various other operations tobe hereinafter described.

Draw chain 36 is centrally located within l land 2), which drivecoupling 48 is connected to the draw chain drive sprocket 46 through adrive shaft 49 held in frame I by bearings 50 and I. The draw chainmaybe lubricated by continuous immersion in a suitable oil reservoirlocated in the path of the under portion of the chain, but not hereshown. The idler sprocket 41 is located adjacent the die end of frame Iand is mounted on an idle shaft 52 yjournalled in adjustable bearings53. These bearings may be moved longitudinally of the draw bench bymeans of nuts 54 on screw threaded rods 55, for adjustment of the drawchain tension or for removal of the draw chain.

The draw chain 36 has preferably a short pitch, that is, the links aremade as short as possible so that variation in linear velocityof thechain will be kept at a minimum; and the drive motors for the drawingchain preferably have rigid speed control soas to produce as nearlyconstant drawing velocities as are'feasible. By means of this preferredform of apparatus, the drawing speed may be Varied from practically astop up to normal'speed, under no loadl up to heavy drawing load, withrapid and even acceleration, initiated by electrical control operablethrough limit switch 43.

Return chains 31 and 38 are iixed to4 carriage 38, through tie plates56, and are supported and located on either side of frame I, beingengaged by drive sprockets 51 adjacent the die end of said frame and byidle sprockets 58 at the opposite end of said frame. Drive sprockets 51are mounted on a common drive shaft 59, which c arries belt pulley orsprocket 60, and is journalled in suitable bearings 6I. The drive shaftand sprockets are drivenhy electric motor 62 through drive belt orendless chain 53 and belt pulley or sprocket 60. The return chain idlesprockets 58 are located on common idle shaft 64 journalled inadjustable bearings 65. Means for adjusting the tension of return chainsand for permitting their ready removal are here provided inthe form ofthreaded rods 66 and adjusting nuts 61 provided thereon. Return chains31 and 38 are recessed in chain guards 68 for protection of both chainsand operator. Suitable means may be provided for lubricating suchchains,A

movement of the carriage on its return to theA die head is positivelycontrolled, thus eliminating the necessity for employing previously usedshock absorbers or cushioning devices to stop the carriage at thediehead. The two return chains 31, 38 are preferably provided 4to insurealignment of the drawing carriage with the die head upon its approachthereto, but a single chain or cable may be vused with satisfactoryresults. The acceleration and deceleration of the drawing carriage onits return travel may be accurately controlled through 'one or more ofthe aforementioned limit switches, as here shown by switches 40, 4I, and42, which switches are actuated by the drawing carriage trip arm I8.

Other elements of the drawing section of the draw bench which should benoted at this point in the description are the two chain releasing cams69 and`18. As aforementioned, the carriag'e 30 is positively connectedto the draw chain 36 by a hook 35 carried by the carriage. Fixed uponthe shaft which supports -hook is a hook release lever 1I (Figs. l and9), which is mounted in a. substantially horizontal posi tionand extendsforward of the drawing carriage on one side thereof. On the extremity ofrelease lever 1I is. a cam follower in the form of a roller 12, adaptedto engage and ride up the contour of cam 69 (Fig. 2) located adjacentthe die head of the drawing section'of the draw bench, or of'stop cam-10located at .the other extremity of the draw bench. At either cam theaction of release lever 1I and its roller 12 is to lift hook 35 out ofengagement with drawing c hain 36, thereby bringing carriage 30 to rest.

Cam 69 is provided for the purpose of releasing the carriage hook fromthe draw chain when the carriage jaws have failed to engage theworkpiece or in case of breakage of the work-piece during forward travelof carriage 30. In either event, there is no drawing tension on thechain. If the carriage 30 has engaged work-piece 8 through the properclamping engagement of jaws 33 and 34 upon the work, the drawing tensionexerted on draw chain 36 will lift the chain and the engaging carriagehook 35 sufficiently high to\ permit hook release lever 1I and roller 12to clear the cam 69. Thus the normal drawing operation will continueuntil the work-piece is free of drawing die 4. At this point, Idrawingtension isy immediately released and the draw chain tends to fall anddisengage itself from the hook 35.

Cam 10 functions as a safety device and hook adjusting mechanism in theevent that hook 35` does not, at the end of the drawing operation andwhen drawing tension is released, release itself from the chain butfalls therewith. In such case, the release lever 1I and its cam follower12 contact cam 10, with the result that the hook 35 is positively raisedand disengaged from the chain 36, and reset in its raised position, thuspreventing the continuously traveling chain 36 from dragging the drawhead 30 oil the end of the bench,

or preventing otherA injury to the assembly.

Draw head in Fig. 9, and which are adapted to grip the-workpiece at thedie head 3.` These jaws areso arranged that Vone jaw may advance` oradjust itself relative` to the other, and relative to the work-piece togrip the pointed end 9 thereof and exert an axial drawing force thereondespite any irregular formation or non-axial alignment of saidWork-piece end. Further it maybe noted that the jaws are actuatedthrough a linkage',

which will be described hereinafter, by means of Aapproach, thereto, andrise thereon the forces exertedby the draw chain 36 on the chainengaging hook 35.

The carriage or draw head 39 is provided with a transverse shaft'journalled in lthe frame thereof. Centrally on said shaft is keyed theclevised end (see Fig. 9) of carriage hook 35. This hook has alink-engaging 'portion 16 which is arcuate in form (see Fig. 2) toconform with a link of the draw chain, the said arcuate portion beingpreferably adapted vto engage somewhat` more than 90 of arc on anyparticular link. Also keyed to shaft 15, at one end thereof, and locatedoutside the frame of carriage 39, is the hook release lever 1| and its`cam contacting roller 12. The keyed angular relationship of hook 35 andhook release lever 1| on through shaft 15 is such that when lever 1| isin its lower position, its roller 12 would engage cam'69 or stop cam 19,on

thereby raising hook 35.

Also keyed to shaft 15 between forked portions of the clevised end ofhook 35 is a crank lever 11 extending in a generally vertical directionabove top .plate 18 of carriage 39, said hook 35 and crank lever 11substantially forming a bell crank oscillatable with said shaft 15, inaccordance with the forces imparted to the hook by means of the drawchain 36, or to the hook release lever 1| by means of the cams 69 or 19.

Disposed laterally and approximately centrally of carriage 39, above topplate 18, is pin 19 supported and retained in bearing blocks 80, 8|. Os-

cillatable on pin 19 is a centrally disposed crank 82 which extendsupwardly therefrom in a generally vertical direction. Adjustable link 83connects the upper extremities of crank 82 to crank lever 11, wherebycrank lever 11, adjustable'link 83, and crank arm 82 form, with theframe of the. carriage, a quadricecrank linkage.

Preferably integrally formed with the lower portion of crank 82 is aprojection forming a latch 84 adapted to be engaged by pawl 85, wherebS1the quadric-crank linkage actuated by hook35 or release lever 1| may belatched with the hook in its raised position in a manner which will bemore fully described hereinafter.

Also oscillatably mounted on pin 19, on either side of crank 82, arejaw-actuating levers 86 and 81, which levers have portions extending ina generally vertical direction above pin-19 in normally parallelrelationship with crank arm 82, and jaw-actuating portions extendingbelow pin |19 to act as lever arms. Jaw-actuating levers 86 and 81 areindependently oscillatable on pin 19 .and are inter-related in theiraction by a double acting spring 88 and associated parts. At the lowerextremities of said jaw-actuating levers are adjustable links 89 and 99connecting to work-engaging jaws 33 and 34, respectively. Said jaws areslidable on converging ways 9| (see Fig. 9). The latterly describedportion of the actuating linkage for each jaw may be referred to as aslider-crank linkage, said linkage comprising a jaw-actuating lever, anadjustable link, and a jaw slidable on a converging way.

To provide for convergence of the jaws, and for the angular movement ofadjustable links 89, 99 with respect to levers 86, 81 and the jaws 33,34, suitable ball-and-socket connections 92 have been provided betweeneach of said levers and each of said adjustable links and between eachof said links and each of said jaws.

Approximately central of the length of th crank 82 on either side, andin the directions of oscillation thereof. are recessed. concavebearing2,331,953 'portions or seats 93, substantially semi-cylindrical inform.On the upper extremities of :lawactuating' levers `86, 81` on eitherside, and in the( directions of oscillation thereof, are similarv 5recessed, concave bearing portions 94, substantially semi-cylindrical inform and adapted to lateral alignment with the corresponding bearingportions 93 on'crank 82.

level of recessed bearing portions 93, has an aperture 95 extendingtherethrough in a direction substantially/tangential to the arc ofrotation thereof.` Extending through aperture 95, in approximately thesame plane as contains the quadric-crank linkage and normallyperpendicular to crank 82, isadjustable tie bolt 96 threaded at eitherend, to receive. adjusting nuts 91. Mounted preferably on the forwardend of the tie bolt 96, in the direction of draw, is bearing mem- `ber98 engaging crank 82 and jaw-actuating levers 86,' 81 in theaforedescribed bearing portions 93 and 94,*respectively. 'Ihe saidbearing member 98, which is axially slidable on tie bolt 96 andpositionable thereon by means of nuts 91, extends laterally across crank82 and across the jaw-actuating levers 86, 81, and is adapted to engagewith either of said jaw-actuating levers or said crank independently, orat times with all of them simultaneously. For engaging the oppositebearing portion of crank 82, or the opposite bearing portions injaw-actuating levers 66, 81, is a second bearing member 99 similarlymounted on said tie' bolt 96. 'I'he two bearing members 98 and 99 areprovided with semi-cylindrical or convex bearing surfaces adapted toengage in the aforesaid semi-cylindrical or concave bearing recesses ofthe crank and the levers.

'Ihe bearing member 99, slidableon tie bolt 96, serves further as aspring seat for double-acting spring 88, which spring is mountedsurrounding the said tie bolt 96 on that portion of .the tie bolt whichextends, to the left as viewed in Fig. 7, toward the jaw portion of thedraw head 39. An opposing spring seat |99 is located at the end of tiebolt 96 and is slidable thereon, being adjustable for position by meansof adjusting nuts 91. i Levers 86, 81 and crank 82 are cooperativelyrelated by means of the aforementioned doubleacting spring, tie bolt,spring seats, and bearing members. The two-fold purpose of the spring,and associated elements is, briey, (1) to tendjo keep levers and crankin the same axial line so that they may function substantially as onesplit lever oscillatable on the pin 19, and yet permit the levers toadvance or retract relative to each other in response to movement of thecrank, and in response to the relative positions assumed by thework-engaging jawsv as they positively and separately engage the work;and (2) to store jawopening energy by compression in the spring wherebythe spring may effectuate movement of the levers to assist in theopening of the jaws, as will hereinafter be specically explained. Ad-

justabilities afforded in the various links, and the yieldability of thespring permit ready accommoldation of the apparatus to work and shape.

For engaging the aforementioned latch 84, the

pawl 85 is pivotally mounted on pin |9|, fitted in suitable bearings |92located in the base of car` 7u riage or draw head 39. 'A spring |03connects pawl 85 andan anchoring pin |94, and tends to lic-ld the pawlagainst either latch 84 (Fig. 7), or the base of crank 82 under the saidlatch. For moving said pawl from its latched position under latchl 84, alongitudinally-extending trip rod |95 Crank 82, at theof varying sizeing movement of the said quadric-crank linkageV to take place.

The operation of the carriage will not be enlarged upon since it isfully set forth in our divisional application, Serial No. 341,677,above- .mentioned a Mandre'l section The preferred means of presentingwork-pieces to die 4 will now be described with reference Vto Figs. 3,4, 5, and 6, as well as to Figs. 1 and 2. Along the mandrel section ofthe bench, which is thatnportion of the bench located on the stockfeeding` sideof the die head 3, are a plurality of mandrel-supportingmembers 24. The portion of the mandrel section of the bench between anend mandrel-supporting member 26, shown in Fig. 3, and themandrel-supporting member 24 adjacent the die head 3, shown in Fig. 2,is not illustrated in the drawings, since it will be apparent that,regardless of the length of the on said rollers. Tubular shells I6 aremounted through apertures in block I.

IEnd mandrel-supporting member 26 (Figs. 3 ande) is associated with'andforms part of the mandrel end frame 21. Two' supporting .rollers II3 arejournalled on end frame 21 and on them is rotatablal disc-like block I4similar to bloks I II Vin the other mandrel-supporting members 24. Onopposite sides of the axis of rotation of the block II4, suitablymounted in apertures ||5 are the ends of the tubublar shells I6. Alsosuitably journalled in restricted bushed portions ||6 of the'aperturesare the end portions of the mandrel Y rods I0 and I2. These mandrel rod'end portions extend through the said apertures to make connections tothe mandrel manipulating mechanisms.

To impart stability to end mandrel-supporting member 26, a third uppersupporting and restraining roller ||1 is mounted in a curved chana nelmember IIB hingedly connected to one side' tubular shells I6, anyconvenient number ofv mandrel-supporting members 24 in the for shown inFig. 2, may be provided. The end mandrel-supporting member`26, as shownin Figs. 3 and 4, is mounted upon a mandrel end frame 21. In the form ofthe invention illustrated, there are two sets of mandrel rods andcooperating tubular shells. These mandrel rods are preferably rotatableabout a common axis located centrally therebetween so that eitherrmandrel rod I0 or mandrel rod I2 may be aligned with die 4. In Fig. 3the lower mandrel rod I0 is shown in forward position corresponding tothe eries will have a locus describing a frustum of a ber v26, areprovided to support the tubuiarshells I6 and indirectly the mandrels,throughout their length, and for constraining the path of rotationthereof. a

Each mandrel-supporting member 24 comprises essentially a frame basestructure25, on which are suitably journalled two supporting rollersIII) adapted to support a disc-like block III, adapted to be rotatedwith its track portion I|2 bearing 24, including the endmandrel-supporting mem- 65 of the end frame 21, as at IIS, and retainedin position over block I I4 by means of a pin connection, as at |20,with'a link |2| hingedly connected to end frame 21,'as'at |22, the linkI2I having an extension thereof adapted to carry counter- YWeight |23.

. (see Figs. 3 and 5). Air cylinder |21, linkage. |28,

and angularly movable gear segment |29 in toothed engagement with pinion|26, are adapted to impart rotational movement to shaft '|24 and therebyto the mandrel rods, rst inpne direction and then in the otherdirection, through an angle of approximately 180. Adjustable stops |30,|3| e are located on end frame 21 in relation to gear segment |29 tolimit4 the rotational movement of said gear segment in either direction.These adjustable stops maybe so arranged that when gear segment |29 isbrought in contact with one or the other stop upon its rotation, amandrel rod and bulb will be in proper alignment with the draw die 4.

Mounted on shaft |24 between the end mandrel-supporting member 26 andthe mandrel rotating mechanism just describedis another-disclike block|32 bearing on rollers |33 suitably journalled on mandrel end kframe 21.This block I 32 is adapted to support manipulating mechanisms I'34, |35for the mandrel rods I6 and I2, respectively. These manipulatingmechanisms comprise suitable double acting' pistons and piston rods |36and |31 adjustably connected to the end portions of the mandrel rods.The manipulating mechanisms are preferably operableby means pfcompressedair but other suitable motive means may be employed. Theadjustable couplings |38 between the end portions of mandrel4 rods |0,|2 and the piston-rods |36,` |31 permit slight adjustment of the positionof each mandrel tolocate its mandrel rod -bulb correctly with respect tothedie, but are primarily provided 4to make convenient the interchangeof various sizes of mandrel rods.

The manipulating mechanisms |34 and |35 are adapted to longitudinally oraxially move the mandrel rods and bulbs into and out-of registry withthe die in response to control which will now be described. Themechanisms are adjustable for longitudinal position to initially correctany appreciable error in registry oi' bulb and die. This adjustment isobtained by means of suitable spanner nuts |33 located in apertures inthe block |32, and adapted to engage threads on mechanisms |34 and |35,said mechanisms being keyed to shaft |24, as at |40, to prevent relativerotation, while permitting relative longitudinal adjustment.

To make clearthe function of the various elements of the mandrel sectionjust described, certain parts of its operation will now be explained.Each manipulating mechanism |34, |35 is adapted to move a mandrel rodand bulb into registry with the die 4 at the beginning of a drawingoperation. Upon the beginning of a'drawing operation the friction of thematerial being drawn over the mandrel rod bulb immediately places themandrel rod in tension which must be resisted by the mandrelmanipulating mechanism, the end mandrel-supporting member, and thethrust bearing provided on the end of the shaft |24. The channel member||8 and upper roller ||1 in end mandrel-supporting member are adapted tomaintain the block ||4 in vertical position and resist the overturningcouple which may be imparted thereto by the drawing force on a mandrelrod and reacting force 'in theV shaft |24. vBushed portions IIB-havebeen provided in the apertures 5 in block ||4 to support and locate themandrel rods |8 and I2, and to prevent overfiexing thereof and thetransmission of iiexure to the mandrel manipulating mechanisms. i

Cil

Mounted on shaft 24 between end mandrelsupporting member 25 andmanipulating mechanisms |34 and |35 are two limit switch dogs |4| and|42 in the form of radial amis extending in opposite directions albngapproximately the same diametrical line. Located approximately centrallyof mandrel end frame 21 beneathshaft |24 are two limit switches |43 and|41 adapted to be engaged and actuated respectively by limit switch dogs|4| and |42. Rotational movement of shaft |24 is adapted to bring onelimit switch dog into position to actuate one limit switch, and oppositerotational movement ofL shaft |24 is adapted to reverse the position ofthat limit switch dog,while the other limit switch dog engages andactuates the second limit switch in alternate fashion. Limit switches|43 and |41 are electrically inter-connected with spring-held solenoidvalves |48 and |43 which are in pneumatic circuit with the pressuresource and the manipulating mechanisms |34 and |35. A thirdy solenoidvalve '|50 is in pneumatic circuit with the pressure source and the aircylinder |21 for rmandrel rotating cylinder |21, and is connected acrossyan electric power source |5| through ratchet-type relay 52, which isactuated by a control circuit connected across power source 5| throughboth limit switch 44 and limit switch 45. Limit switch 45 may bereplaced by or used in parallel with a push button |53, the latteralternative being illustrated in Fig. 6; and this limit switch 45, ifemployed as such, should be of the momentary contact type, whereas theother linut switches described herein are of the ordinary circuit makingand breaking type. By positioning limit switch furtherA from the diehead3 than limit switch 44, on the main frame of the draw bench: thesuccessive action (45, then 44) of these limit switches (upon returnmovement of carriage 30) will energize and move the ratchet of theratchet-type relay |52 to actuate solenoid valve |50, thereby directingair to one side of the mandrel rotating cylinder |21, and thenopen thecircuit through relay |52; and upon the reverse successive opening (44,then 45) of the limit switches, they will have no eiect upon the mandrelrotating cylinder |21 until the-next cycle, switch 44 being moved onlyto select the circuit through relay |52.

For controlling the-supply of air to either side of the mandrelmanipulating mechanisms |34 and |35, the solenoid valves |48 and |49 arealso connected across the power source |5| through ylimit switches |45and |41, respectively, and

through the opposite terminal of lixnit switch v44 on the main frame ofthe draw bench. Since the limit switches |45 and |41 are operable uponrov Y tation of the mandrel rods and shaft |24, their successive effectupon the system will be automatic following the actuation of mandrelrotating cylinder |21.

'I'he inter-relation of the electric and pneumatic control system forthe mandrel rods will become more apparent as the operation of the drawbench generally is described in further detail hereinafter.

tating the mandrel rods. The pressure source V tioed nmit switches u andu on the main frame of the draw bench are inter-related-with the limitswitches |45 and |41 on the mandrel end frame.

Solenoid -valve |50 controls the air, or other 52 movement of thecarriage 30 toward the dieA head 3 will begin. The limit switclr dog 35on carriage 30 will iirst'strike the limit switch 45 which, because ofthe previous closing of limit switch 44 on its first terminal in thecircuit to solenoid |50 (as in Fig. 6) on movement of the 'carriage awayfrom the die, will by momentary electrical contact (dotted position ofswitch 45, Fig. 6) energize the coil of ratchet-type relay |52, closingor opening the switch thereof. The push button |53 is shown as adaptedto serve the 'same purpose as switch 45. The solenoid valvel |50 havingbeen energized or de-energized and actuated by relay- |52 to direct airto the mandrel rotating cylinder |21, a piston therein.

A pressure medium, supply Vto either side of the mandrel rods I0 and |2approach the end of dos,` e. g., dog |4|, will engage a limit switch, e.g.,4

their rotational movement, a limit switch |46, closing the 'same (as inFig. 6) and thereby partially close the circuit tofa solenoidvalve,

e. g., 48, adapted to control the supply of air to` drel rod will beadvanced upon the closing of' the limit switch 44 upon its secondterminal (shown dotted in Fig. 6), later to be effected as the carriagemoves toward the die, since when one limit switch |46 or |41 is closed,the other is necessarily opened, as here constructed.

At a position along the main frame of the draw bench nearer the die head3, the limit switch dog 39 on the carriage 30 engages and operates limitswitch 46. Upon the movement of limit switch 48, the eld control of thereturn drive motor 62 is, in the operation here described, modied tobring the return speed of the carriage to a substantially constant basevalue.

- At a position along`the main frame of the draw bench still nearer thedie head, the said limit switch dog 39 engag'es and operates limitswitch 44. Upon the movement of limit switch 44 to its second terminal(dotted position, Fig. 6), the energizing circuit to the mandrelrotating cylinder |21 is completely disconnected, without effect thereonsince the circuit is normally open at' switch 45 or push button 153; andthe circuit to the previously selected manipulating mechanism solenoidvalve, -e. g., |48, is closed, whereupon a mandrelmanipulating'mechanism, e. g., |34, is

operated to move a piston rod, e. g., |36, mandrel rod, e. g., 6, andbulb, e. g., connected thereto forward into registry with die 4, asshown in the gures, thereby moving a tube 8 substantially into drawingposition in said die, At this position the pointed end 9 of the' tubeextends through die 4 for engagement by the jaws 33 and 34 of thedrawing carriage 30.

Upon further approach of the carriage 30 to the die head the limitswitch dog 39 strikes and actuates successive limit switches 4|, 43, and42, which in that order respectively decrease the speed of the returndrive motor 62 by armature shunt control, decrease` the speed of vthedraw.

chain 36 to a pre-set initial drawing speed, and stop the motion of thedrawing carriageas it approaches the die head byv applying `dynamicbraking through the drive motor 62.

As carriage 36 comes to rest at die head 3, trip rod contacts the diehead and releases pawl If stopped the draw chain would then be clampsthe jaws 33 and 34 upon the pointed end 9 of the tube 8, and brings themandrel-rod bulb into nal registry with the die 4.

' n Before continuing with the description of the operation, it may bepointed out that if the jaws should fail to engage4 the end ofthe tubethere will be no tension Aon the chain 36 and the hook 35 will not besubstantially raised. Rather'than permit Ythe carriage to travel out thefull length of the frame, vmeans for stopping the car.- riage andreturning it again to the die head are provided. The roller follower120i hook release lever 1| will strike the cam 69, which will raise thehook release lever and will release the hook from the chain, whereuponthe carriage 36 may have a short return travel back to the die head tore-engage tube 8. i

Assuming, however, that the jaws have engaged the end of the tube uponthe falling of'hook 35 into the draw chain, the motion of the carriageoutward under drawing tension will continue asv first actuate and engageIlimit switch 42, resetting the same and electrically disconnecting fromcir. cuit the return drive motor 6,2 so that the return chains 31 and38, xedly connected to the carriage, may cause reverse rotation of4 thedrive motor 62 against no electromagnetic forces.

The limit switch dog 39 will next resetthe'limit switch 43 and causeacceleration -of the drive chain 3 6 from its initialA slow speedl tonormalv drawing speed. p v

The next limit switch 4|. will be merely reset without effect upon thecycle of operations.

Likewise the next limit switch 44 will be reset, toits first position(as shown in full line in 6) closing inpart the circuit to theratchet-type relay |52 with asyet no effect thereon. But the.

resetting of this limit switch 44, however, opens the circuit to thesolenoid valve, e. g., |48, which will then be spring actuatedto'reverse the ow of air, o'r other 'pressuremedium to the opposite sideof a piston in a. manipulating mechanism, e. g.,

|34. tending to withdraw a mandrel rod, e. g., l0,

and bulb, e. g., from registry-with'die 4. v'Ihis tendency, however,will remain ineffective while n there is drawing tension onla tube 8,but will be ing at a slow speed as here provided, immediately upon theengagement of the hook 35 with the draw chain, the carriage 30 beginsits'travel away from the die head and the drawing of [the tube begins.Drawing tension through the chain, hook, carriage, jaws, tube, mandrelrod bulb, and mandrel rod raises the hook to its normal position, wherecrank 82 is latched by pawl85,

adapted to withdraw the mandrel rod and bulb upon completion of thedrawingn operation.

The next limit switch `will be merely reset without effect upon thecycle of operations. The final limit switch will be reset to an ineffective position without affecting :the cycleof operations, whereuponthe electric and pneumatic control system will be then in condition foroperation as described at the beginning ofthis drawing cycle. Y

' Before completing the description of the operation, it is to be `notedthat vsuccessive drawing cycles differ in that the switch of relay |52will be 'open' inv one ca'se andclosed inthe next; likewise solenoidvwill bespring-held in one case and electro-magnetically-held.in thenext; and likewise elements |4|, |46,- |48, |34, |33, I0, and will befactive in one case,vand correspondingy elements |42, |41, |49, |35,|31, l2, and-|3 respectively will be active in thev next, as far yasconcerns the actual drawing operation'.

After passing these.limit switches, preferably located'wlthin a.distance from the die head corresponding to the minimum length oi.' tubeto be handled, the carriage 30 will continue to be drawn out alongtracks 3| on main frame I by draw chain 36 until tube 8 is drawncompletely through die 4. When tube -8 makes its exitfrom die 4,

`there will be an immediate release of drawing tension throughout thedraw bench; and the recoiling eiect of the tube 8 in connection with thestored energy in the spring 88 will immediately open the jaws 33 and 34o! carriage, whereupon the tube 3 will'be released and allowed to fallonto any suitable unloading devices arranged therebeneath (not shown).At the same time the release of tension in the draw chain 3B will permitthe chain to fall from engagement with the hook 35'and the carriage willcome to rest. Also the pressure of air against the piston in themanipulating mechanisme. g., |34, will then be eiIective to move themandrel rod and bulb out of registry with die 4 and to retract the sameinto and within its protective tubular shell I6.

The carriage is then in'position for a repetition of the cycle abovedescribed. Mandrel indexing in succeeding cycles will reset themanipulating mechanism selection switches |46 and |41, and it will beapparent to one skilled in the art that-the cycle of operations whichmay be employed with the lpresently disclosed draw benchl is adapted toa wide variation.

As may be understood from the foregoing de- `scription, the operation ofthe draw bench is sub.-

stantially' automatic. Certain special features may be particularlypointed out. To prevent accidental damage, both of the manipulatingmechanisms |34 and |35 are normally retracted and only advance after theclosing of two independent limit switches, and a mandrel rod bulbremains in the die only during the drawing operation. The work may beflood lubricated externally by a stream of oil from a suitable pipesupply, which may be arranged on the mandrel section of the draw bench,or, of course, the work may be iary devices with which this draw benchhas been described are not essential to its useful operation, and thatmany other combinations and relations of the parts and associateddevices may be employed without departing from the nature and scope ofthis invention as deilned in the appended claims.

What is claimed is:

1. In an apparatus for die drawing metal shapes including a die andmovable drawing means for drawing a work-piece through said die, thecombination comprising work-holding means adapted to support thework-piece as it is drawn through said die, means for moving saidwork-holding means bodily into and out of axial alignment with said die,and separate means actuated by the movement of said drawing means forinitially advancing the work-piece into said die when in alignmenttherewith.

2. In an apparatus for die drawing metal shapes including a die andmovable drawing means for drawing a work-piece through said die, thecombination comprising work-holding means adapted to support thework-piece as it is drawn through saiddie, means actuated by themovement of said drawing means for moving said work-holding`means bodilyinto and out of axial alignment with said die, and separate means forinitially advancing the Workpiece into said die when in alignmenttherewith.

3. In an apparatus -for die drawing metal shapes including a die andmovable drawing means for drawing a work-piece through said die, the`combination comprising work-holding means adapted to support thework-piece as it is drawn through said die, means actuated by themovement of said drawing means for moving said work-holding means bodilyinto and out of axial alignment with said die, and separate means forinitially advancingthe workpiece into said die when in alignmenttherewith, said work-advancing means being separately actuated by themovement of said drawing means.

4. In a metal working apparatus including a die and a movable draw headfor pulling a metal shape through said die,v the combination comprlsinga plurality of work-holding members each adapted to support a metalshape adjacent said die, means for successively translating said Work-Vholding members bodily into a-nd out of axial alignment with said die,and separate means associated with each said work-holding member forinitially advancing the supported shape to said die' when in alignmenttherewith.

5. In a metal working apparatus including a die and a movable draw headfor pulling a metal shape through said die, lthe combination comprisinga -plurality of work-holding members, means actuated by the movement ofsaid draw head for positively moving each said work-holding memberbodily into and out of axial ali-gnment with said die, and separatemeans associated with each said work-holding memb'er'for initiallyadvancing a supported shape to said die when in alignment therewith.

6. In a metal working apparatus including a die and a movable draw headfor pulling a metal shape through said die, the combination comprising aplurality of. work-holding members bodily rotatable around a common axisand means actuated by the movement of said draw head for positivelyindexing each said work-holding member into and out of axial alignmentwith said die.

7. In a metal working apparatus including a die and a movable draw headfor pulling a metal shape through said die, the combination comprising aplurality of work-holding members, means actuated by the movement ofsaid draw head for positively moving each said Work-holding memberbodily into and out of axial alignment with said die, and separate meansassociated with each s'aid work-holding member and ing means bodily intoand out of axial align- I ment with said die,separate means foradvancresponsive to carriage movement.A

9. In an automatic draw bench, a die and a draw carriage, means formoving said carriage in the performance of a drawing operation, meansfor supporting material to be drawn adjacent said die, means foradvancing and prometal shape through said die, the combinationcomprising a plurality of work-holding members, means for successivelytranslating said "workholding members bodily into and out of axial,

alignment.. with said die, and separate means associated with each saidwork-holding member and actuated bythe movement of said draw head forinitially advancing a supported shape to said die when in alignmenttherewith.

-. .11. In a metal working apparatus-including a die and a movable drawhead -for pulling a metal shape throughsaid die, the combinationcomprisingv a plurality of work-holding members bodily rotatable arounda common aids,.and

means for positively indexing each said workholding member by bodilyrotating the same into and out of axial yalignment with said diethroughout its work-supporting length. Y

12. In a metal working apparatus including a shape through said die, thecombination comprising a plurality of work-holding members bodilyrotatable about a common axis, means for positively indexing each saidwork-holding member into and out of axial alignment with said die,

and separate'means associated with eachl said work-holding member forinitially advancing a supported shape to said die when in alignmenttherewith.

13. In a metal working apparatus including a -die and a movable drawhead for pulling a metal shape through said die, the combinationcomprising a plurality of work-holding members bodily rotatable arond acommon axis, means for positively indexing each said work-holding memberinto and out of axial alignment with said die, and separate meansassociated with each said work-holding member and actuated by themovement of said draw head for initially advancing a supported shape tosaid die when in alignment therewith. y

14. In a metal working apparatus including a die and a movable draw headfor pulling a metal shape through said die, the combination comprising aplurality of work-holding members bodily rotatable around a common axis,means actuated by the movement of said draw head for Rositively indexingeach said work-holding member into and out of axial alignment with saiddie, and separate means associated with each said workholding member andactuated by the movement die and a movable draw head for pulling a metal'4'5 of said draw head for initially advancing a supported shape to saiddie when in alignment therewith.

15. In a draw bench, a die, a draw device adapted to grip a work-pieceprojecting through said die and draw it through the die, a rotarycarrier at the entry side of said die, means rotatably supporting saidcarrier with its axis par-.

allel to and laterally offset from the pass line of said die, aplurality of work supporting members incorporated in said carrier anddiametrically arranged concentrically of the axis of rotation thereof,vfor bodily movement in a circular path intersecting the pass line ofsaid die. one of said supporting members being disposed in loadingposition to receive a work-piece and the other in axial alignment withsaid die to support the work-piece being drawn through said die, powermeans operatively connected to said carrier for rotating the same, toreverse the position of said supporting members, Y whereby the loadedsupporting member is aligned with said die and the empty one is disposedin said loading position, and means for initially moving the work-piecein said die-aligned supporting member endwise into and through said diefor gripping by said draw device.

16. In a* draw bench, a die, a draw device adapted to grip a tubeprojecting through said die and draw it through the die, a rotarycarrier at the entry side of said die comprising a pair of' elongatevtubular members and a plurality of coaxial circular blocks spaced alongsaid members, said members being diametrically arranged concentricallyof the axis of rotation of said blocks, with one member in axialalignment with said die and the other member laterally oiset therefrom,means rotatably supporting said ,blocks at their peripheries, powermeans operatively connected to said carrier to rotate the same andreverse the position of said tubular members, manipulating devicescoaxial with said members at the'ends thereof remote from said die, arod connected to each vmanipulating device and extending through` theassoicate tubular member, and a mandrel secured to the forward end ofeach rod, a tube to be drawn being inserted endwise over said mandreland supportingly received in the tubular member in-said offset positionfor delivery into axial alignment with the die upon actuation of saidpower means, the mandrel of the tubular member in alignment with the diebeing shifted forwardly by actuation of the associated manipulatingdevice to push the tube thereon through the die for gripping by saiddraw device.

17. In a draw bench as deiined in claim 16,

wherein said tubular members are provided with a plurality oflongitudinally spacedinternal 'guides for supporting the tube receivedtherein 19. In a draw bench, a die, a rotary carrier including aplurality of work supporting members at the entry side of said die forpresenting successive work-pieces to said die in longitudinal alignmenttherewith, a work-piece being loaded endwise into one of said supportingmembers at a point laterally offset from said die while anotherwork-piece is being Withdrawn -from the other supporting member anddrawn through said die, power means for rotating said carrier to bringthe loaded supporting member into registry with said die, meansoperable. to advance a work-piece endwise into the die with its endprojecting through the die, a draw head including means for grippingsaid projecting end, means for moving the draw head to draw the grippedwork-piece through said die, and means actuated by movement of said drawhead back toward said die for actuating said power means and saidadvancing means sequentiallyin the order named.

20. In a draw bench, a die, a rotary carrier at the entry side of saiddie and incorporating a pair of diametrically disposed work supportingmembers for alternate movement into longitu- 'dinal alignment with saiddie, means peripherally .supporting said carrier for rotative movement,power means operatively connected to said carrier to rotate the same andreverse the position of said supporting members, means associated witheach of said supporting members for initially advancing a supportedwork-piece into .position 'projecting through said die when in alignmenttherewith, means actuated by rotation *of said carrier for preselectingsaid advancing means for alternate operation, a draw headv includingmeans for gripping the projected workpiece, means for moving the drawhead to draw the gripped work-piece through the die,means actuated bysaid draw head during return'movement thereof toward said die foractuating said power means to rotate said carrier and means subsequentlyactuated by said draw head during said return movement thereof. foractuating the preselected advancing means to advance the succeedingwork-piece into position projecting throughl said die for subsequentdrawing therethrough.

' RAYNAL W. ANDREWS., Ja. ARTHUR T. DEILY.

CERTIFICATE QF coRRETIoN.

.Pnt N o. 2,551,955. 'A octoberw, 1915.

' RAYNAL W. ANDREWS, JR.,'ET AL.

It is hereby certified that error appears inl the printed specificationof the'above numbere patent requiring correction as fo-llws: Page 2,s'econd column, line 7l, for'. 'head 50" read 4 head' 5-; page5,'second' column, line 11, for "tubublar" read -'tbular'; page 9,secoxxdoolumn, line h5, claim 16, for assoicat' read asociate; and that'the .said' Letters Patent -should be read with this correction thereinthat the same may' conform tothe record of, the case in .the PatentOffice, I'

Sigled-andsealel this 7th day or D eqember, A. D'. 1915.

5 Henry Ven Arsdale, l (Seal) Actngcommissionerof Patents. b

. DlscL,-A|M.ER 2,331,953-f-Rayml W. Andrews, Jr., New Kensington, andArthur 1'. Deug, Pimburgh, Pa.. METALwonII'NG APPARATUS. Patent datedOct. 19, 1943. gisclgimer led Feb. 14, 1946, by the assignee, Aluminum`Company of manca.

\ Hereby gnters Athis.dilaimer to claims 44, 1 1, 12, and 15 ofsaid'specicaton. l

[Ojm'alv Gazgug March 19, 1946.]

